Hey Guys....
Bruce...
As far as carrying upside down...
That's not really the case...
I carried a Gerber MKII upside down for years in it's factory sheath,with never so much as a problem..It's all in how you attach the knife/sheath to the pack..
As far as synthetic sheaths go,, if it properly designed to be carried upside down, you should Never have a problem.
My Spyderco Moran has been attached to my daypack Upside down for almost a year, and hasn't budged from it's sheath..
I agree with you if the sheath is Not designed,,or improperly designed for the job,, Yes then you may loose the knife.
I attach all of my pack knives using E-tape or military duct tape.
Lashing a knife or sheath down with paracord is Utterly Useless.
You'll be lucky to get a mile with it before it starts flopping around as the knots and lashing loosen up.
Some type of tape is the absolute best way to suspend a sheath from LBV gear or pack straps.No one I know,,or have ever seen lashes a sheath down with paracord.It just doesn't stay tight enough for long enough.
If you want to carry a knife on a pack, have a sheath or a belt loop designed to fit the particular belt and carry it horizontal on the pack belt.
This puts the knife in easy reach.
Truthfully though you should always be carrying your knife on your person and not on your gear..
ttyle Eric...
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Eric E. Noeldechen
On/Scene Tactical
http://www.mnsi.net/~nbtnoel
Custom,Quality, Concealex Sheaths.
Leading The Way In Synthetic Sheathing.